SPRINGFIELD-Gov. Pat Quinn Wednesday announced a six-year, multi-billion transportation project with nearly $500 million to upgrade Chicago's Circle Interchange, though the project's fate remains uncertain as lawmakers still need to approve $2.7 billion of the funds.

Accompanied by Transportation Secretary Ann Schneider at the Capitol, Quinn proposed $1.12 billion for high-speed rail from Joliet to St. Louis, nearly $700 million in upgrades to the CTA Red Line, more than $600 million for METRA and nearly $50 million to connect I-57 and I-294 in the South suburbs.

All told, Quinn estimates the plan will cost $12.62 billion and create roughly 140,000 jobs across the state through 2019.

"Our economy depends on our location and our transportation, and over the last five years since I've been governor, we've invested more money in transportation than in any five-year period in Illinois history," Quinn told reporters.

The plan calls for improvements to 2,142 miles of highway and to 517 bridges across the state with funding coming from $7.2 billion in anticipated federal funds and $1.9 billion from the state treasury. However, additional bond authorization will need to make up much of the difference, and the Legislature will need to authorize $2.7 billion in funds by May 31.

But Quinn's call to issue additional bonds isn't expected to be easy considering the state's rocky financial status since Illinois became the nation's least credit-worthy state in January.

Following that credit downgrade, the state was forced to delay a $500 million bond issue to be used for state road, school and construction projects. In order for the Legislature to pass a new bond issuance, 60 percent of members in both the House and the Senate will need to approve the idea.

"I've talked to our legislative leaders," Quinn said. "I think they understand how important it is to pass that."

As lawmakers continue to craft a 2014 budget, Quinn's plan would allocate for next year roughly $2.24 billion for road projects, $128 million for public transit, $224 million for rail and $68 million for airports in Peoria, Rockford and Springfield.

On the top of Quinn's list seemed to be making the improvements at the I-90/94 and I-290 Circle Interchange in downtown Chicago.

"It's a spaghetti bowl that's been around now for 50 or 60 years. It's reached its life expectancy and it really needs to be brought up to 21st century standards," Quinn said.